Oxygen chemical properties, Chapter

One of the most ubiquitous multiple-component contaminants that reaches the soil and deeper subsurface layers is crude oil and its refined products. In the subsurface, these contaminants are transformed differently by various mechanisms (Cozzarelli and Baber 2003). Crude oil contains a multitude of chemical components, each with different physical and chemical properties. As discussed in Chapter 4, the main groups of compounds in crude oils are saturated hydrocarbons (such as normal and branched alkanes and cycloalkanes without double bonds), aromatic hydrocarbons, resins, and asphaltenes, which are high-molecular-weight polycyclic compounds containing nitrogen, sulfur, and oxygen. 

The chemistry of saturated heterocyclic compounds is characteristic of their functional group. For example, nitrogen compounds are amines, oxygen compounds arc ethers, sulfur compounds are sulfides. Differences in chemical reactivity are observed for three-membered rings, e.g., epoxides, whose enhanced reactivity is driven by the relief of their severe ring strain. This chapter discusses heterocycles that are aromatic and have unique chemical properties. 

Phthalocyanines were chosen for these experiments because they are electronic semiconductors and because they are quite stable materials — an important consideration in fabricating any practical gas-detecting device. A considerable body of literature exists describing the physical and chemical properties of the phthalocyanines. A review of the work prior to 1965 is contained in the chapter by A. B. P. Lever in Volume 7 of Advances in Inorganic Chemistry and Radiochemistry (2). Electrical properties of phthalocyanines have been receiving increased attention in recent years. The photoconductivity of metal-free phthalocyanine has been studied in detail (3,4). Electrical properties of lead phthalocyanine have been studied extensively, especially by Japanese workers (5, ,7,8i). They have also studied the alteration of the conductivity of this material upon exposure to oxygen ( ,10.). The effects of a series of adsorbed gases (0, , CO, and NO) on the conductivity of iron phthalo-... 

One of the distinctive chemical properties of non-metallic elements is their ability to combine with metals forming simple binary compounds in which they are the negative constituent. It is the purpose of this chapter to deal with such simple compounds of the more pronounced non-metals chlorine, bromine, iodine, oxygen, sulphur, and nitrogen. 

How do we get energy from these compounds In this section, you will learn how complete and incomplete combustion can be expressed as chemical equations. Combustion in the presence of oxygen is a chemical property of all hydrocarbons. (In Chapter 13, you learned about some physical properties of hydrocarbons, such as boiling point and solubility.)... 

The sixth-group elements sulfur, selenium, and tellurium are much less electronegative than their congener oxygen, which was discussed in Chapter 6, and their chemical properties are correspondingly distinctive. 

We now discuss chemical reactions in further detail. We classify them as oxidation-reduction reactions, combination reactions, decomposition reactions, displacement reactions, and metathesis reactions. The last type can be further described as precipitation reactions, acid-base (neutralization) reactions, and gas-formation reactions. We will see that many reactions, especially oxidation-reduction reactions, fit into more than one category, and that some reactions do not fit neatly into any of them. As we study different kinds of chemical reactions, we will learn to predict the products of other similar reactions. In Chapter 6 we will describe typical reactions of hydrogen, oxygen, and their compounds. These reactions will illustrate periodic relationships with respect to chemical properties. It should be emphasized that our system is not an attempt to transform nature so that it fits into small categories but rather an effort to give some order to our many observations of nature. 

Zirconia (Zr02) is an extremely versatile ceramic that has found use in oxygen pumps and sensors, fuel cells, thermal barrier coatings, and other high-temperature applications, all of which make use of the electrical, thermal, and mechanical properties of this material. Proof of the interest and usefulness of zirconia can be seen from the voluminous literature found on this material. This chapter is intended to provide a concise summary of the physical and chemical properties of all phases of zirconia that underlie the appropriate engineering applications. 

Much of the chemistry of oxygen can be rationalized in terms of its electronic structure (2s 2p ), high electronegativity (3.5) and small size. Thus, oxygen shows many similarities to nitrogen (p. 412) in its covalent chemistry, and its propensity to form H bonds (p. 52) and double bonds (p. 416), though the anionic chemistry of 0 and OH is much more extensive than for the isoelectronic ions N , NH and NH2. Similarities to fluorine and fluorides are also notable. Comparisons with the chemical properties of sulfur (p. 662) and the heavier chalcogens (p. 754) are deferred to Chapters 15 and 16. 

In this chapter, I wish to explore the possible role of photochemistry (an inherently disequilibrium process) in formation of the planets and smaller bodies in the solar system. As was seen in the planetary examples above, the small differences in chemical properties of the stable isotopes of abundant light elements, especially carbon, nitrogen, and oxygen, provide key information regarding nebular chemistry. The rapid attenuation of light in a cloud of dust and gas requires that the irradiation region be continuously replenished, so that chemistry and dynamics are intimately interrelated. 

The immense importance of dissolved free oxygen for the microbial decomposition of organic substance has already been discussed at length in the Chapters 3, 5 and 6. Due to its chemical properties which make it one of the most effective... 

As stated in Chapter 2.1.2, water (H2O) and hydrocarbons (C H ) are the most abundant molecules in space and both were delivered to earth from space (i.e. are not produced on earth). In Chapter 2.5.1, we discussed the unique physical and chemical properties of water. Table 2.23 shows data that explain the chemical stability. However, H2O is chemically reactive, and Fig. 2.31 and reaction (5.4) show the central role of H2O in (biogeo-)chemical cycling between oxygen (O2), carbon dioxide (CO2) and hydrocarbons (C ,Hj,). As discussed in Chapter 2.4.4, the water-splitting process proceeds in plants under the influence of light and enzymes. Nevertheless, we have seen that H2O is chemically decomposed (reaction 5.21, see below for more examples) and produced in many reactions (5.2c, 5.3, 5.31, 5.32 and 5.33). We have also already mentioned that H2O is photolyzed in the upper atmosphere (outside the climate system) ... 

---